The invention pertains to security devices to prevent deception of coin acceptor units which allow persons to pay for operation of varied kinds of machinery, such as vending machines, coin operated car washes, and many other kinds of machines which are intended to be operable only upon receipt of proper payment by the coin acceptor unit, and more particularly pertains to prevention of a particular kind of such deception which a thief may cause by exposing the coin acceptor unit to a moving magnetic field.
Though coin acceptor units are of varied kinds, they all have mechanisms and circuitry for allowing operation of some electrically powered machinery if and only if the required payment has been received by the coin acceptor unit. One possible way of interfering with proper operation of the coin acceptor unit, so as to cause it to improperly allow the machinery operation when a proper coin has in fact not been received, is to expose the circuitry of the coin acceptor unit to a moving magnetic field. Even without gaining physical access to the interior components of the coin acceptor unit, the thief may expose the coin acceptor circuitry of the mechanism to a moving magnetic field, by simply moving a strong hand-held magnet near the outside of the case containing the mechanism. By Faraday""s law, the moving magnetic field lines will induce currents to flow in the circuitry of the coin acceptor unit.
Applicants have recently become aware that it is becoming increasingly common for thieves to steal operation of coin-operated car wash machines by this magnetic deception method. However, applicants believe that this practice represents a threat to the security of a wide variety of machinery activated through coin acceptor units.
So, there is a need, met by applicants"" invention, for a coin acceptor unit security apparatus which will detect the presence of a moving magnetic field, and, upon detection of same, temporarily prevent the flow of the electrical power needed to allow the coin acceptor unit to activate the machinery, for a desired short xe2x80x9ctime outxe2x80x9d period, and which will further, upon expiration of said time out period, automatically restore the coin acceptor unit to its normal settings, so that it may then be used to activate the machinery through deposit of the required coinage, and which will allow said normal settings to be maintained until the next detection of a moving magnetic field. There is further a need for such a security apparatus which may be used to block magnetic deception of any coin acceptor unit.
Applicants"" apparatus meets these needs, in its preferred embodiment, by means of circuitry containing a magnetic switch for detection of the moving magnetic field, a timer for controlling the duration of the time out period, and circuitry for controlling timer activation and power interruption and resumption.
The invention is a security apparatus for preventing deception of a coin acceptor unit used to allow only paid operation of machinery, where such deception is caused by use of a moving magnetic field which a thief may produce by moving a magnet near the coin acceptor unit to induce currents in the mechanism""s circuitry so as to cause a false determination that a proper coin has been received and allow unpaid operation of the controlled machinery; said apparatus comprising means to detect a moving magnetic field and further comprising a time out means to, upon detection of said field, turn off power needed for operation of the coin acceptor unit and the machinery, and to keep said power off for a predetermined time out period, and to restore the coin acceptor unit to normal settings, allowing normal operation of the. coin acceptor unit and machinery after expiration of said time out period, until such time as a moving magnetic field is again detected.